Chapter 9: Chemical Reactions

metal and nonmetal

Which combination of elements forms crystalline solids that will dissolve in water, producing a solution of ions that conduct an electric current?

burning a sheet of paper

Which of the following represents a chemical change?

Element

A pure substance that cannot be decomposed into anything simpler by chemical or physical means is called a(n)

mixture

has unlike parts and a composition that varies from sample to sample.

physical change

a change of the state of a substance but not the identity of the substance

compound

a pure chemical substance that can be decomposed by a chemical change into simpler substances with a fixed mass ratio

chemical change

a change in which the identity of matter is altered and new substances are formed

atom

the smallest unit of an element that can exist alone or in combination with other elements

chemical bond

compounds are formed when atoms are held together by an attractive force.

molecule

a tightly bound group of atoms that retains the chemical and physical properties of that substance

chemical reaction

a change in matter where different chemical substances are created by forming or breaking chemical bonds

chemical energy

a form of energy involved in chemical reactions associated with changes in internal potential energy; a kind of potential energy that is stored and later released during a chemical reaction

photosynthesis

new chemical substances are produced in green plants through the process

chemical equation

concise way of describing what happens in a chemical reaction

molecule

The smallest particle of a compound or a gaseous element that can exist and still retain the characteristic chemical properties of a substance is a(n)

octet rule

a generalization that helps keep track of the valence electrons in most representative elements; atoms of the representative elements (A families) attempt to acquire an outer orbital with eight electrons through chemical reactions

octet rule

What rule states that atoms attempt to acquire an outer orbital with eight electrons?

ionic bond

chemical bond of electrostatic attraction between negative and positive ions

heat of formation

energy released in a chemical reaction

formula

describes what elements are in a compound and in what proportions

ionic compounds

chemical compounds that are held together by ionic bonds; that is, bonds of electrostatic attraction between negative and positive ions

covalent bond

a chemical bond formed by the sharing of a pair of electrons

covalent compound

chemical compound held together by a covalent bond or bonds

single bond

covalent bond in which a single pair of electrons is shared by two atoms

double bond

covalent bond formed when two pairs of electrons are shared by two atoms

polyatomic ions

groups of two or more atoms that are bound together tightly and behave very much like a single monoatomic ion.

triple bond

covalent bond formed when three pairs of electrons are shared by two atoms

valence electrons

The electrons that participate in chemical bonding are (the)

covalent

Which type pf chemical bond is formed between two atoms by the sharing of electrons?

-ide

An inorganic compound made of only two different elements has a name that always ends with the suffix

water

Dihydrogen monoxide is a compound with the common name of

law of conservation of mass

same as law of conservation of matter; mass, including single atoms, is neither created nor destroyed in a chemical reaction

coefficients

A chemical equation is balanced by changing (the)

the same number of each kind of atom on both sides of the equation

A balanced chemical equation has

oxidation-reduction reaction

a chemical reaction in which electrons are transferred from one atom to another; sometimes called “redox” for short

oxidizing agents

substances that take electrons from other substances

reducing agent

supplies electrons to the substance being reduced in a chemical reaction

combination (chemical) reaction

a synthesis reaction in which two or more substances combine to form a single compound

decomposition (chemical) reaction

a chemical reaction in which a compound is broken down into the elements that make up the compound, into simpler compounds, or into elements and simpler compounds

replacement (chemical) reaction

reaction in which an atom or polyatomic ion is replaced in a compound by a different atom or polyatomic ion

ion exchange reaction

a reaction that takes place when the ions of one compound interact with the ions of another, forming a solid that comes out of solution, a gas, or water

carbon dioxide and water vapor

Since wood is composed of carbohydrates, you should expect what gases to exhaust from a fireplace when complete combustion takes place?

combination

When carbon burns with an insufficient supply of oxygen, carbon monoxide is formed according to the following equation: 2C + 0² —> 2CO. What category of chemical reaction is this?

aluminum

Of the elements listed below, the one with the greatest chemical activity is

True

A mixture can be distinguished from a pure substance because it can be separated by physical means.

True

The representative A-group family of elements have one to eight valence electrons.

False

An atom becomes a positive ion by gaining an electron.

False

Atoms gain or lose electrons in chemical reactions in order to increase their energy state.

True

Atoms gain or lose electrons in order to attain a valence orbital arrangement like that of neon gas.

False

Ionic bonds occur between atoms from adjacent chemical families in the periodic table.

False

The covalent bond holding a molecule of carbon monoxide together is a shared pair of electrons.

True

Three hydroxide ions are needed to form a neutral ionic compound with an aluminum ion.

False

The "-ide" ending in nitrogen dioxide tells you that this is an ionic compound.

False

The "2" in Mg(OH)₂ tells you that the charge of the hydroxide ion is (-2).